Steam-engine



3 Sheets-Sheet 1.

(No Model.)

O.M.LONG. STEAM ENGINE.

, Patented Sept. 15 1885.

INVENTOR 1 0u7'tis- M.L"o'ng Jig 722:3 Attorney 1.

N, FEI'ERS, Pholo-Lilhcgraphur, Washin ton, 0. cv

(No Model.)

- 3 Sheets-Sheet 2. G. M. LONG.

STEAM ENGINE.

Pa en pt". 1511335- Fw. 2 y

WITNESSES INVENTOR UurtzlsJVELong.

N4 PETERS, Phuwumu m hon Washington, D. c.

3 Sheets-Sheet 3. G. M. LONG.

STEAM'ENGINE.

(No Model.)

Patente'd3eptf15, 1885.

UNITED STATES PATENT OFFICE.

CURTIS M. LONG, OF ALLEGHENY, PENNSYLVANIA.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 326,303, datedSeptember 15, 1885.

Application filed July 8, 1885. (No model.)

To all whom it may concern.-

Be it known that I, CURTIS M. LONG, a citizen of the United States, anda resident of Allegheny, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements in Steam-Engines of the oscillating-piston type; and I do hereby declare thatthe following is a full, clear, and exact description thereof, whichwill enable others skilled in the art to which it appertains to make anduse the same.

The object of my invention is, the construction of a steam-engine of theoscillating-piston type, accurately balanced by means of duplicatepistons, cranks, pitmen, and crank-arms, which,moving in oppositedirections, equalize momentum and strains, and with centers properlyplaced to avoid jar or shock from suddenly-reversed movements, and toobtain a machine with small friction, high speed, great efficiency, andcompactness.

In the drawings, Figure 1 is a side elevation showing cylinder andeasing with the working parts resting on centers. Fig. 2 is a frontelevation with cylinder in section. Fig. 3 is the reverse side ofcylinder, partly in section, showing the septa and valve arrangement.Fig. 4. is a central section of the double piston, showing theirconstruction in two parts with hollow sleeve and packing.

In Fig. 1 the crank-arm A is attached to and is a part of the shaft 0,which is oscil-. lated by the piston D, as shown in Fig. 2, and thecrank-arm B is a part of the sleeve F and piston E. These crank-arms areplaced opposite each other- J being center-at such angles that when theyreach their centers or end of stroke the pistons will be even and readyfor the return-stroke. The travel of crank-arms and pistons iscontrolled by the system of cranks G H, and therefore, on account of theangles of pitmen varying at different points on each stroke, the pistonswill move part of their strokes at slightly different speeds; and it isfor the purpose of accommodating this movement that the duplicatepistons are independent of each other, D being rigidly attached to shaft0, and E to the hollow sleeve and crank-arm B, as before stated, andshown in Figs. 2 and 4.

The pistons D and E move in one cylinder, and are operated by the valvessubstantially as if they were one and made for the purpose of operatingone crank-arm and pitman. The cranks G and H are placed at such anglesto plane a through shafts I and G as will bring them one to its upperand the other to itslower center at the same time, and as these centersfall both upon the same side of the plane through shafts O and I itfollows that the cranks are not exactly opposite.

For economy and compactness, it is a great object to employ one cylinderfor inclosing the two double oscillating pistons; but I find itadvantageous to separate them slightly in their cylinder, because ifbrought face to face in contact, owing to the slight variations in speedin certain parts of their movement above referred to, there will beslight overlapping, so that the edges of the pistons against which thesteam impinges to drive them will not at all times be in perfectalignment. On account of this slight overlapping of the pistons in theirmovement, which would cause the steam to impinge upon small portions oftheir sides instead of only their edges, they would, if in contact, bepressed laterally against the cylinder-heads, which would cause.friction and resistance to their free movement. To obviate thisdifficulty, I insert the web or diaphragm x, which may be cast with thecylinder or fixed rigidly to it, between the adjacent faces of thepistons.

The result, therefore, is that pressure of the steam can never operateto induce injurious friction in the movement of the pistons, but only tooscillate them. This same result of preventing injurious friction may beaccomplished in other ways; but this I deem preferable.

The web is slightly less in width than the extent of travel of thepistons within the cylinder, which insures perfectly even wear upon theweb, and prevents the formation of shoulders in the metal near the pointof clearance between the septa and the edges of the pistons. Thevalve-port is in length equal to the thickness of the two pistons andinterposed web. The result is that the steam will be admitted equally oneither side of the web to drive each piston in substantial unison withthe other. It will be seen that by this arrangement, the parts on eitherside being duplicates of each other, there is obtained, first, a perfectbalance against gravity, and, second, a balance the direction of strainsis reversed twice in each revolution.

In Fig. 1 the dotted lines inclosing E E indicate the piston attached tohollow sleeve F,

and the dotted lines inclosing J J are the septa or partitions thatdivide the cylinder into its upper and lower working-chambers. Thedotted circles within J J are the valve-chambers. K and L are thepitmen, and M the stuffing-box gland. a is the plane through axes ofshafts, and d the planes through shaft I and cranK-eenters. Theduplicated double pistons D and E are shown in Fig. 2, and in section inFig. 4. N is the cylinder, 0 cylinder-head.

In Fig. 3 J J are the septa; P Q, the balanced hollow cylindricaloscillating valve within the septa; R, the steam-ports, and S theexhaustports.

I am aware that oscillating valves have been used in engines of thisclass, but not within the septa, as I use them, so that one valve servesfor both pistons without enlarging the cylinder or taking up roomoutside of it.

e indicates the steanrinduetion pipe, and f, in dotted lines, thesteamways in the cylinder leading to the valve. 9 indicates the waysleading to the exhaust-pipe h. There is an opening, z, in thecylindrical valves, a little larger inarea than the combined areas ofthe two port-openings 7a and Z, so that the steam-- pressure is nearlyequalized on all parts of the valves to balance them and to avoidfriction, which might hinder their action, but at the same time to leavea slight preponderance of pressure of the valve upon its seat.

The valves are operated by cranks and rods, as shown at T, fromeccentrics properly set upon the driven shaft I, Fig. 2. These valvesreceive steam in their ends and admit steam on opposite sidesof thedouble pistons D and E, and thus force them through the are of theiroscillation, and then admitting steam on the reverse sides force themback to the point of starting. This oscillatory movement is transferredthrough the crank-arms A and B and pitmen K and L to the driven shaft I,which is rotated thereby, and from which the power may be transmitted byany ordinary means in use.

Fig. 4. shows a central section of the duplicated double pistons D and Ewith the hollow sleeve F and packing-strips properly adjusted by spiralsprings. U are packing-rings held in place by the same means. The ring Ushown outside the piston D is let into thecylinder, as shown, Fig. 2.

I am aware that engines with oscillating pistons are not broadly new,and I claim only my improvements upon such engines, which I understandto .be as follows:

1. In an engine ofthe oscillating-piston type, the duplicatedoublepistons D and E, working side by side within a single cylinder,and the duplicate crankarms, cranks, and pitmen arranged to workopposite to each other, substantially as and for the purpose set forth.

2. In combination with the cylinder N, the duplicate double pistons Dand E, working side by side, and the web ac, between the pistons,substantially as set forth.

3. The balanced oscillating valves and ports.

within the septa, in combination with the cylinder N and the duplicatedouble pistons D and E, substantially as set forth.

4. The combination of the sleeve F, the crank-arm B, and piston E withthe crankarm A, shaft O, a nd piston D, substantially as and for thepurpose described.

In testimony whereof I have hereunto subscribed my name.

I CURTIS M. LONG.

Vitnesses:

MARoUs S. HOPKINS, v0. 1?. ELWELL.

